$ \left(\dfrac{1}{64}\right)^{\frac{1}{2}}$
Figure out what goes in the blank: $\Big(? \Big)^{2}=\dfrac{1}{64}$ Figure out what goes in the blank: $\Big({\dfrac{1}{8}}\Big)^{2}=\dfrac{1}{64}$ So $\left(\dfrac{1}{64}\right)^{\frac{1}{2}}=\dfrac{1}{8}$